1. Field of the Invention
The present invention relates to an improved agitator structure which is particularly adapted for use in automatic washers which provide short stroke, high stroke rate agitation.
2. Description of the Prior Art
Most conventional automatic washers provide agitation at relatively low stroke rates, with a long agitator stroke. By way of an example, a conventional washer manufactured by Whirlpool Corporation provides an agitator stroke length of 198.degree. at a stroke rate of 68 oscillations per minute. In contrast, a high stroke rate washer may have a stroke rate of 180 oscillations per minute with a stroke length of 100.degree..
Some conventional washers use an agitator having vanes which flex during agitation of the clothes load. For instance, such agitators are described in U.S. Pat. Nos. 3,296,840 and 3,307,383, both assigned to Whirlpool Corporation. Such agitators have been found to provide very good overall washing performance. Good washing performance requires that a careful balance be struck between the sometimes competing considerations of washability, fabric abrasion, and lint generation. In developing an agitator for a high stroke rate, low stroke angle washer, the applicants found that a flexible vane agitator suitable for conventional machines provided less than desirable performance.
In particular, use of a conventional flexible vane agitator in a high stroke rate washer was found to produce undesirable levels of fabric abrasion and lint generation. Thinning the vane material to increase the amount of vane flexure was found to reduce the lint generation but, very surprisingly, provided a higher level of fabric abrasion. It was also found that, using the conventional agitator material such as polypropylene, providing an agitator with extremely flexible vanes in a further attempt to reduce fabric abrasion would shorten the useful life of the agitator due to vane breakage.